Exporting entire world from blender to unreal without exporting same asset multiple times
I don't have much experience with this, so I am going to give you an answer that is a basic starting point.  If you haven't already you should download an add on from Epic Games called &quot;Pipeline: Send to Unreal&quot;.  In this add on there are some options about &quot;exporting collections&quot; and &quot;combining child meshes&quot;, as well as various FBX related controls.   Further research into these settings should help to answer your question more.
https://epicgames.github.io/BlenderTools/send2ue/quickstart.html